Globally, approximately 10 million new patients every year suffer from brain injury, which is likely to become the 3rd leading cause of death of human beings by 2020. It is generally known that a primary injury, a direct result of the brain injury, cannot be recovered. However, some studies have reported that most cell death induced by the traumatic brain injury occurs several hours after the initial injury. A typical secondary brain injury is an ischemic injury, which accompanies an increase of the intracranial pressure (ICP) and a decrease of the cerebral perfusion pressure (CPP).
Currently, there are two major medical imaging techniques for evaluating the degree of a brain injury; computed tomography (CT) and magnetic resonance imaging (MRI). The magnetic resonance imaging has higher resolution and sensitivity and, thus, is better able to detect cerebral edema than the computed tomography. However, the magnetic resonance imaging is disadvantageous compared to the computed tomography because it requires longer image acquisition time than the computed tomography and a patient should keep a fixed posture during imaging. For these reasons, it has been reported that the high sensitivity of the magnetic resonance imaging has no significant clinical superiority over the computed tomography, especially for a patient with the traumatic brain injury who requires urgent treatment.
Especially, keeping a fixed posture during the magnetic resonance imaging would be more disadvantageous for pediatric patients. For example, pediatric patients with the brain injury are usually under sedation or general anesthesia before the magnetic resonance imaging as they should keep a fixed posture. The sedation or general anesthesia may cause complications in the heart and the respiratory organs, which may combine with the primary injury and trigger the secondary injury.
On the contrary, the computed tomography may be greatly effective to patients requiring urgent interventions, such as patients with traumatic brain injury or stroke. However, the computed tomography may have high user-dependency whereby the degree of structural abnormality is differently measured according to the observers. Accordingly, as an effort to reduce the user-dependency by standardizing diagnosis of brain injury based on the computed tomography, various classification systems have been suggested. Of those classification systems, Marshall classification that Marshall suggested in 1991 has been the most widely used. Marshall classification is based on six (6) categorizations for traumatic brain injury evaluation depending on the structural abnormalities including a volume of brain lesion, an extent of midline shift, compression of basal cistern, and a presence or absence of surgical interventions. Marshall classification is known to provide critical information on the prognosis of patients with the brain injury. However, Marshal classification still cannot overcome the user-dependency.
Accordingly, there has been a demand for developing a new paradigm for a computed tomography analysis system whereby the limits of the existing analysis system can be overcome.
In this regard, Japanese Patent Laid-open Publication No. 2005-237441 (entitled “Method and Apparatus for Supporting Diagnosis of Brain Disorder”) describes a method for providing a more objective diagnosis result for a brain injury, which involves the steps of inputting a brain image of a patient, standardizing the brain image, and, then, carrying out a statistical analysis of the subject brain image by comparing it with a brain image of a normal person.